Just search for "kid tablets" at walmart.com or target.com, and you'll see dozens of brightly colored tablets with rubber bumpers and cutesy names like Kurio, Orbo, Tabby and Meep.

As a parent, I tend to think of these as product spam. It's true, the more reputable makers jam the tablets with age-appropriate content and give parents plenty of controls and tools to incentivize the educational use of the things, but that's still a hard sales pitch for a household that already has two iPads and a Kindle Fire HDX—with more than enough apps, games and interactive books to go around.

But when Fuhu—an El Segundo, Calif.-based company that's been selling its own bright red Nabi tablet for several years—told me they were launching a tablet whose screen measured two feet in diagonal, that got my attention.

A 24-inch tablet sounds like an oxymoron. "That's basically an iMac," several people have told me in unrelated instances. Except that it runs Android, and has a 1080p high-def capacitive touch screen capable of registering 15 simultaneous finger taps, and a built-in battery. Not that the battery will last more than a half-hour, but it's enough to get this 13-pound monster from room to room without having to reboot everything.

Surprisingly, the Nabi Big Tab 24 costs just $550, only a bit more than an entry-level iPad Air. (Fuhu is also releasing a slightly smaller Big Tab, a 20-incher that will cost $450.)

So what happened when I brought my work home with me, and shared the Big Tab with my 6-year-old girl and 3-year-old boy?

ENLARGE

The Big Tab's supersize dimensions allow two children to play on the same device.
Jason Henry for The Wall Street Journal

A huge tablet changes the playing dynamic entirely. The kids play well together when it comes to Lego or puzzles, but they have never been known to share a tablet, except maybe to stare dumbly at it while a movie was playing.

The 24-inch Big Tab lets them do all kinds of things together. In the demo unit that Fuhu lent me, there were two-player games such as air hockey and "Fruit Ninja," drawing studios, puzzles, and even family board games: generic versions of "Candyland" ("SweetLand") and "Chutes and Ladders" (well, "Slides and Ladders").

After I unboxed it, the kids actually played for an hour and a half straight, and in that time, I observed two startling phenomena:

1) They didn't fight, but instead talked and laughed with each other the whole time.

2) They never once loaded up the movies or TV shows, though they knew those were also on the device.

I joined in, getting into some of the longest and most brutal "Chutes and Ladders" battles of my life. I was happy to witness the makings of good sportsmanship as I observed how my kids reacted to both victory and loss. Even my wife, who was initially dubious, admitted that she'd much sooner play a game with the kids on the Big Tab than on our smaller tablets.

The period of blissful harmony was over by the next day. The kids were playing a fire-hose game called "Sprinkle Island," and they got into an altercation over water usage that resulted in my son giving my daughter a scratched face. I was stunned, mostly because they had done so well when playing against each another—why would playing toward a common goal cause such anger?

"Cooperation is much harder than competition, especially for young kids," said
Seeta Pai,
VP of research and digital content at the nonprofit parental-advisory group Common Sense Media. "They are very focused on themselves." Ms. Pai would know—she doesn't just have a doctorate in education from Harvard, but she's got twin 4-year-old girls.

You can tell from reading this that I am not opposed to letting my very active children use tablets in moderation. Yet I make a point to involve myself in the process, so I'm aware of what they're doing, and how beneficial it is to their development.

"If you treat a device like a forbidden fruit, chances are that's how the child is going to relate to it," Ms. Pai told me. "As long as you are achieving the balance, know what works for your child, and are considering the quality of the content, it's OK."

The Big Tab's supersize dimensions provided a stage for my children to play together, and for me to witness those dynamics better. I'm happy to report that they have since made it through multiple levels of "Sprinkle Island," and without further bloodshed.

With the Big Tab, Fuhu found a way to differentiate from the iPads, Kindle Fires and Samsung Galaxy Tabs that dominate the tablet industry. But while size matters, it may not be the only draw for parents looking for an alternative to a TV in a child's room.

The company prides itself on its family-wise software, but we were unable to test the Nabi interface—a youth-focused walled garden of content and tools—on this preproduction device. Instead, we explored the interface on Fuhu's other devices, such as the 8-inch DreamTab, its "Shrek"-"Kung Fu Panda"-"Madagascar"-themed collaboration with
DreamWorks
Animation.

Beyond providing kid-safe photo-messaging apps and cloud storage, and novel utilities like the allowance-earning Chore List, Fuhu is growing on the education front. Its Wings program includes a quiz game with 50,000 questions geared to the common core, that scales from pre-K through sixth grade. There's more to come from Wings as early as this fall, including workbooks and an interactive pen.

Jim Mitchell,
Fuhu's CEO, says the focus on software helps differentiate the company from both the candy-colored knockoffs and the dominant tablet makers.

"We're selling tablets in a different way and it's helped us in what I'll call the slowing of tablet sales," he told me. "We're focused on creating an innovative and immersive experience. Parents don't buy tablets based on speeds and feeds. They say they want the tablet because it has all of these great characters and experiences."

With the Big Tab, that also means more titles geared to a "family board game" night, said Mitchell, who acknowledged that he's talking to
Electronic Arts
,
which handles the digital versions of
Hasbro
's
Milton Bradley and Parker Brothers games, to create large-screen Android apps of the classic titles.

After seeing how my kids took to the Big Tab, I went in search of other examples of collaborative play that wouldn't just rot their brains. The best came from LeapFrog, a company that focuses on the 10-and-under crowd, and uses its licensing of Transformers, SpongeBob, Dora and the like as spoonfuls of sugar to make the education go down.

My kids tried out multiplayer games on a pair of soon-to-be-released LeapPad 3 tablets. The devices have tiny screens, so the collaboration and competition take place when they are wirelessly connected.

There's a drawing game that lets kids sketch sea horses, bugs and buses, then send them to their friends to guess what they've drawn. There's a Pac-Man-like gopher digging game where the players have to work together to gather up food. And there are lots of games like "Kart Racing," where the players learn numbers while going head-to-head on the racetrack.

But even if this was cooperation, the kids were nose down in their devices. They weren't physically engaging each other, like they would on the Big Tab. That's why I got a brief demo of the LeapTV, which launches sometime this fall. Think of it as a Wii aimed at the really wee folk—a motion-controlled gaming console that plugs into your TV, with educational games for kids ages 3 to 8. My children weren't able to try it out, because LeapFrog is still working out the bugs, but from what I saw, it could be a very good way of getting them up and moving—and interacting with each other—on a very big screen. (You'll just have to bring your own.)

LeapTV and the Big Tab don't really compete with each other. LeapFrog is focused on a specific age group, while Mitchell says Fuhu is also trying to win over teens and families with its latest products. But both devices overturn certain notions about screen time and electronic play. And it's about time.

Couldn't games similar to those played on Fuhu's Big Tab also be played on an already existing iMac or Windows 8-enabled computer with a large touch screen? It seems redundant to buy another device solely to have an oversized monitor children (and the rest of the family) can interact with.

This copy is for your personal, non-commercial use only. Distribution and use of this material are governed by our Subscriber Agreement and by copyright law. For non-personal use or to order multiple copies, please contact Dow Jones Reprints at 1-800-843-0008 or visit www.djreprints.com.